Abstract
Microcracks were observed in epitaxial 
thin films grown on (111) Si substrates by chemical vapor deposition (CVD) from 
and 
entrained in 
. A one‐step process and a more commonly used two‐step process were employed. The latter was comprised of an initial chemical conversion of the Si surface, via the deposition of C alone and a subsequent deposition of both C and Si to form the 
film. In contrast, no cracks were revealed in the 
film grown on (100) Si by using either process. However, the growth of high quality, reproducible films occurred only when the two‐step technique was used. The resulting thermal stresses in the 
films deposited on both (111) and (100) Si substrates were calculated. The tensile strength of the deposited single‐crystal films was estimated to be in the range of
. Possible solutions to minimize crack initiation and growth will be discussed.